St. Joseph Medical Center did not have authority over the medical decisions cardiologist Mark Midei made for his stent patients, attorneys for the Towson hospital's former owners said in court Monday as they attempted to separate the institution from the doctor accused of performing unnecessary procedures.

Midei's former patient, Glenn Weinberg, a Baltimore businessman who said he lost at least $50 million because the doctor misled him to believe that he had severe coronary artery disease, is suing the doctor and the hospital, the doctor's former employer.

"St. Joseph hospital didn't control or direct" any medical decisions regarding Weinberg's treatment, Thomas Monahan, an attorney for the hospital, said during the second day of opening statements in Baltimore County Circuit Court. He added that St. Joseph merely provided the space for the physician to perform procedures.

But Monahan did say the hospital believes Midei was correct in performing three stent procedures on Weinberg. Stents are mesh tubes that hold open blocked arteries to improve blood flow.

On Friday, lawyers for Weinberg said Midei's medical findings were flawed and that other cardiologists found no severe blockages requiring stents.

Midei's attorney, Michael Sloneker, who continued his opening statements Monday, argued that Weinberg, who had unknowingly had a small heart attack, needed medical intervention.

Both Midei and the hospital contend that Weinberg's stents were necessary, given his past medical history, angiogram images and other expert opinions, Monahan said. He added that Midei performed the procedures because the benefits outweighed the risks.

Several hundred lawsuits have been filed against Midei and his former employer. The case involving Weinberg, who is a partner at the Cordish Cos., which has developed such projects as Maryland Live, the state's largest casino, is expected to be one of the biggest in terms of the dollar amount sought.

Midei has denied any wrongdoing. He was forced to leave the hospital after the allegations surfaced in 2009. The Maryland Board of Physicians revoked Midei's license in the state in 2011.

Catholic Health Initiatives owned the hospital at the time Midei worked there but put the medical institution up for sale after the allegations left it in financial disarray. The University of Maryland bought St. Joseph last year. Under the sale, Catholic Health Initiatives, not University of Maryland, is responsible for liabilities from the lawsuits.

Midei is now working for a private equity firm called AshHill Pharmaceutical Investments. The company, which invests in the life sciences, was incorporated in his home state of Ohio in 2011 and has headquarters in the Cincinnati area.

Midei is a partner in the business, according to colleague Eric Ott, though he's not listed among the executive team on AshHill's website.

"He evaluates the medical potential of companies seeking investment through AshHill," said Ott, who's also a partner.

Midei has said he struggled to find work after St. Joseph began warning his patients that their stents might have been unnecessary. He sued the hospital for defamation, but the case was dismissed last year. The Maryland Court of Special Appeals upheld the dismissal this past summer.

Monahan, the attorney for St. Joseph, said Weinberg's physician referred him to Midei's practice — MidAtlantic Cardiovascular Associates — not to the hospital.

He said St. Joseph is considered a community hospital, meaning "a place where physicians and private practices treat their patients." He said decisions on how to treat patients are made by the doctor, not hospital administrators. He noted that patients are billed separately by the physicians and the hospital.

Monahan told jurors there is a distinction between the administrative position that Midei held in the hospital's catheterization lab and the clinical care he was providing patients.

He said Midei also didn't receive health and other benefits from the hospital as other employees would.